The postal service could grind to a halt because of fresh strikes as soon as
next month unless a peace deal between unions and Royal Mail is signed in
the next 10 days.

Union sources are giving warning that unless an agreement was signed by a jointly agreed deadline of January 22, further action could be expected with unions returning to “dispute mode” in the bitter row about pay and working practices.

National strikes could be called for as early as next month, without the need for a fresh ballot of postal workers. The overwhelming vote for a national strike among Communication Workers Union members from last September still stands.

A series of rolling strikes last summer, culminating in several days of all-out national strikes in October brought the postal service to its knees, with more than 30million letters and parcels trapped in sorting offices and mail centres.

In early November, Royal Mail and the Communication Workers Union agreed a truce to save the Christmas post from disruption.

Both sides then committed themselves to finding some middle ground in the bitter row about pay and working practices during this strike-free “period of calm”.

But there are fears that if there is no written agreement by January 22, Royal Mail will push ahead with implementing its 2010 management plan, triggering a fresh bout of unrest.

Both sides said they were cautiously optimistic about the outcome. But the next 10 days are vital as both sides committed to paper the results of the talks over the past eight weeks, one source said.

The source told The Daily Telegraph: “Royal Mail want to move to their 2010 plan. If they go ahead and impose changes, there will be industrial action.” Another source described the talks as "painfully slow".

Royal Mail’s decision to press ahead with the 2009 management plan last April, which recommended cuts of 10 per cent, without the agreement of the union, was the trigger for last year's strikes, the worst for two years.

Teams of Royal Mail managers and union officials have been meeting at a series of London hotels over the past two months. The talks have been chaired by Roger Poole, a former chair of the Northern Ireland Parades Commission.

They have been led for the union by Dave Ward, the CWU’s deputy general secretary, and for Royal Mail by Mark Higson, managing director of Royal Mail’s letters business.